Introduction to PMR 446
This is a fairly new allocation for short-range communications using hand-held units only. Being on UHF (446 MHz, as opposed to CB on 27 MHz) it is not compatible with CB sets - CB’s and PMR446’s cannot talk to each other. This service has some advantages over CB, but also some disadvantages...
There are only 8 channels, as opposed to CB’s 80... The maximum transmitted power is .5 watt, compared to CB’s 4 watts... You cannot connect an external antenna to the units, so the shielding effect when used inside metal vehicles cannot be overcome.
Despite the seemingly low transmitted power, for handheld-to-handheld communications, PMR446 will actually out-perform CB in terms of range (it’s all down to aerial efficiency!)... It is license-free, whereas you should have a CB license... There is a huge range of units available, some of which are extremely small - much smaller than CB’s will ever be.
Some companies will claim over 300 “channels” for the PMR446 units, but this is incorrect. You have 8 channels (different frequencies that you can transmit and receive on) but there are ways of making the receiver select who to listen to, so that you do not hear any other users who may be on the same frequency - this can give you over 300 combinations.
Having said this, there are only 8 channels, and if someone else is talking on the same channel as you and the person who wants to hear you is receiving the other user at about the same signal strength it’s likely that you will block each other out and nothing will be heard. This will only become a major problem in areas where there are a lot of users because by the nature of the 1-3km (1-2 miles) range, you will need to be fairly close to them to get problems.
PMR446 can actually be so flexible, ideal for recreational activities as well as for professional uses that many people have PMR’s for family communications, holidays, outings, keeping track of kids etc - irrespective of whether they use CB for other things or not.